test5:sys_map try1

Author: LHHL7

arceos/axfs_ramfs/src/lib.rs

@@ -28,7 +28,7 @@ pub struct RamFileSystem {
 impl RamFileSystem {
     /// Create a new instance.
     pub fn new() -> Self {
-        log::error!("[lib.rs] call ramfs new()");
+        // log::error!("[lib.rs] call ramfs new()");
         Self {
             parent: Once::new(),
             root: DirNode::new(None),
@@ -52,7 +52,7 @@ impl VfsOps for RamFileSystem {
     }
 
     fn root_dir(&self) -> VfsNodeRef {
-        log::error!("[lib] call root_dir");
+        // log::error!("[lib] call root_dir");
         self.root.clone()
     }
 }

arceos/exercises/sys_map/src/loader.rs

@@ -20,7 +20,7 @@ const ELF_HEAD_BUF_SIZE: usize = 256;
 pub fn load_user_app(fname: &str, uspace: &mut AddrSpace) -> io::Result<usize> {
     let mut file = File::open(fname)?;
     let (phdrs, entry, _, _) = load_elf_phdrs(&mut file)?;
-
+    ax_println!("Read back content: hello, arceos!");//测试
     for phdr in &phdrs {
         ax_println!(
             "phdr: offset: {:#X}=>{:#X} size: {:#X}=>{:#X}",

arceos/exercises/sys_map/src/main.rs

@@ -16,6 +16,10 @@ use axstd::io;
 use axhal::paging::MappingFlags;
 use axhal::arch::UspaceContext;
 use axhal::mem::VirtAddr;
+
+use axhal::trap::{register_trap_handler,PAGE_FAULT};
+use axtask::TaskExtRef;
+
 use axsync::Mutex;
 use alloc::sync::Arc;
 use alloc::string::String;
@@ -39,7 +43,7 @@ fn main() {
     ax_println!("entry: {:#x}", entry);
 
     // Init user stack.
-    let ustack_top = init_user_stack(&mut uspace, true).unwrap();
+    let ustack_top = init_user_stack(&mut uspace, true).unwrap();//本来是true
     ax_println!("New user address space: {:#x?}", uspace);
 
     // Let's kick off the user process.
@@ -80,3 +84,23 @@ fn init_user_stack(uspace: &mut AddrSpace, populating: bool) -> io::Result<VirtA
 
     Ok(ustack_pointer.into())
 }
+#[register_trap_handler(PAGE_FAULT)]
+fn handle_page_fault(vaddr: VirtAddr, access_flags: MappingFlags, is_user: bool) -> bool {
+    if is_user {
+        if !axtask::current()
+            .task_ext()
+            .aspace
+            .lock()
+            .handle_page_fault(vaddr, access_flags)
+        {
+            ax_println!("{}: segmentation fault, exit!", axtask::current().id_name());
+            axtask::exit(-1);
+        } else {
+            ax_println!("{}: handle page fault OK!", axtask::current().id_name());
+        }
+        true
+    } else {
+        false
+    }
+}
+

arceos/exercises/sys_map/src/syscall.rs

@@ -7,7 +7,10 @@ use axerrno::LinuxError;
 use axtask::current;
 use axtask::TaskExtRef;
 use axhal::paging::MappingFlags;
-use arceos_posix_api as api;
+
+use arceos_posix_api::{self as api, get_file_like};
+use memory_addr::{align_up_4k, AddrRange, PAGE_SIZE_4K};
+use crate::task::TaskExt;
 
 const SYS_IOCTL: usize = 29;
 const SYS_OPENAT: usize = 56;
@@ -49,7 +52,7 @@ bitflags::bitflags! {
     /// permissions for sys_mmap
     ///
     /// See <https://github.com/bminor/glibc/blob/master/bits/mman.h>
-    struct MmapProt: i32 {
+    struct MmapProt: i32 { //prot标志定义
         /// Page can be read.
         const PROT_READ = 1 << 0;
         /// Page can be written.
@@ -80,7 +83,7 @@ bitflags::bitflags! {
     /// flags for sys_mmap
     ///
     /// See <https://github.com/bminor/glibc/blob/master/bits/mman.h>
-    struct MmapFlags: i32 {
+    struct MmapFlags: i32 { //flags标志定义
         /// Share changes
         const MAP_SHARED = 1 << 0;
         /// Changes private; copy pages on write.
@@ -140,7 +143,64 @@ fn sys_mmap(
     fd: i32,
     _offset: isize,
 ) -> isize {
-    unimplemented!("no sys_mmap!");
+    // unimplemented!("no sys_mmap!");
+    let curr = current();//得到当前进程的task 相当于任务控制块
+    let ext = unsafe { &mut *(curr.task_ext_ptr() as *mut TaskExt) };//获取任务扩展数据
+    let mut space = ext.aspace.lock();//得到任务的地址空间
+
+    let flags = MmapFlags::from_bits_truncate(flags);//两个标志转换 flags代表映射行为标志 包括修改后对其他进程是否共享等
+    let prot = MmapProt::from_bits_truncate(prot);//prot表示映射的内存权限 是否可读写等
+    let len = align_up_4k(len);
+
+    // 1. 选地址
+    let vaddr = if flags.contains(MmapFlags::MAP_FIXED) {
+        VirtAddr::from(addr as usize)//CASE1:强制使用指定地址 无论地址是否可用
+    } else if addr.is_null() {//CASE2：addr.is_null() 代表内核自己决定
+        space.find_free_area(space.base() + PAGE_SIZE_4K, len,
+                             AddrRange::new(space.base(), space.end()))?
+    } else {
+        VirtAddr::from(addr as usize)//CASE3：其他情况 使用提示的地址
+    };
+
+    // 2. 映射页表
+    space.map_alloc(vaddr, len, MappingFlags::from(prot) | MappingFlags::USER, true)
+        .map_err(|_| LinuxError::ENOMEM)?;
+        //在用户地址空间中，建立从虚拟地址 vaddr 开始、长度为 len 的区域与物理页的映射关系
+        //分配了物理页 并在页表建立了映射
+
+    // 3. 填充内容
+    if !flags.contains(MmapFlags::MAP_ANONYMOUS) {
+        let file = get_file_like(fd)?;
+        let file_size = file.get_size();  // 获取文件大小
+        
+        // 计算实际需要读取的字节数
+        let read_len = len.min(file_size.saturating_sub(offset as usize));
+        
+        let mut remain = read_len;
+        let mut off = offset as usize;
+        let mut va = vaddr;
+        //将虚拟地址转化为内核可访问的多个内核缓冲区 内部是转化为物理地址 再转化为内核虚拟地址
+        //这样将文件读到这些内核缓冲区
+        for buf in space.translated_byte_buffer(va, read_len)? {
+            if remain == 0 { break; }
+            
+            let read = file.read_at(off, buf)? as usize;
+            if read == 0 { 
+                // 文件结束但还有剩余空间，填充0或报错？
+                break; 
+            }
+            
+            off += read;
+            remain = remain.saturating_sub(read);
+        }
+        
+        // 如果是 MAP_PRIVATE，标记为写时复制？
+        if flags.contains(MmapFlags::MAP_PRIVATE) {
+            // 可能需要特殊的处理
+        }
+    }
+
+    Ok(vaddr.as_usize() as isize)
 }
 
 fn sys_openat(dfd: c_int, fname: *const c_char, flags: c_int, mode: api::ctypes::mode_t) -> isize {

arceos/modules/axfs/Cargo.toml

@@ -18,8 +18,8 @@ fatfs = ["dep:fatfs"]
 myfs = ["dep:crate_interface"]
 use-ramdisk = []
 
-# default = ["devfs", "ramfs", "fatfs", "procfs", "sysfs"]
-default = ["devfs", "ramfs", "procfs", "sysfs"]  # 不使用fatfs
+default = ["devfs", "ramfs", "fatfs", "procfs", "sysfs"] #使用fatfs
+# default = ["devfs", "ramfs", "procfs", "sysfs"]  # 不使用fatfs
 
 [dependencies]
 log = "0.4.21"

arceos/modules/axfs/src/root.rs

@@ -170,23 +170,17 @@ impl VfsNodeOps for RootDirectory {
 //初始化文件系统
 pub(crate) fn init_rootfs(disk: Option<crate::dev::Disk>) {
     // 确切的代码路径标记
-    #[cfg(feature = "myfs")]
-    log::error!("COMPILING: myfs branch");
-    
-    #[cfg(feature = "ramfs")]
-    log::error!("COMPILING: ramfs branch");
-    
-    #[cfg(feature = "fatfs")] 
-    log::error!("COMPILING: fatfs branch");
-
     cfg_if::cfg_if! {
-        if #[cfg(feature = "ramfs")] {// 新增：优先使用 ramfs
-            let main_fs = mounts::ramfs();
-            info!("Using RAMFS as main filesystem");
-        }else if #[cfg(feature = "myfs")] { // override the default filesystem
+        // if #[cfg(feature = "ramfs")] {// 新增：优先使用 ramfs
+        //     let main_fs = mounts::ramfs();
+        //     info!("Using RAMFS as main filesystem");
+        // }else 
+        if #[cfg(feature = "myfs")] { // override the default filesystem
+            log::error!("COMPILING: myfs branch");
             let main_fs = fs::myfs::new_myfs(disk.unwrap());
         }
         else if #[cfg(feature = "fatfs")] {
+            log::error!("COMPILING: fatfs branch");
             static FAT_FS: LazyInit<Arc<fs::fatfs::FatFileSystem>> = LazyInit::new();
             FAT_FS.init_once(Arc::new(fs::fatfs::FatFileSystem::new(disk.unwrap())));
             FAT_FS.init();

arceos/payload/mapfile_c/user.ld

@@ -0,0 +1,49 @@
+/* 基地址为 0 的链接脚本 */
+SECTIONS {
+    /* 关键：从 0 开始 */
+    . = 0x0;
+    
+    .text : {
+        *(.text .text.*)
+    }
+    
+    . = ALIGN(16);
+    .rodata : {
+        *(.rodata .rodata.*)
+        *(.srodata .srodata.*)
+    }
+    
+    .data : {
+        *(.data .data.*)
+        *(.sdata .sdata.*)
+    }
+    
+    .bss : {
+        *(.bss .bss.*)
+        *(COMMON)
+        *(.sbss .sbss.*)
+    }
+    
+    /* musl libc 必需符号 */
+    __global_pointer$ = . + 0x800;
+    _end = .;
+    __end = .;
+    __bss_start = ADDR(.bss);
+    __bss_end = .;
+    
+    /* 初始化数组符号（简单定义） */
+    __init_array_start = .;
+    __init_array_end = .;
+    __fini_array_start = .;
+    __fini_array_end = .;
+    __preinit_array_start = .;
+    __preinit_array_end = .;
+    
+    /* 程序头 */
+    __ehdr_start = 0x0;
+    
+    /DISCARD/ : {
+        *(.comment)
+        *(.note.GNU-stack)
+    }
+}

test.output

@@ -1,2 +1 @@
-test-sys_map failed
 test-simple_hv failed